I seem to recall hearing that at some point in the 1960s, the availability of FHA financing for homes in new developments was made contingent upon those developments' having a "curvilinear" street layout. Not sure how this general adjective would have been processed into strict legalese, but there are some neighborhoods in New Hope and eastern Plymouth that seem to fit the bill at a quick glance.I'm mostly curious about grids though. I know sight lines have a little to do with it, and if memory serves from City Planning classes crime prevention as well.
As for the notion that winding, curvy streets would prevent crime -- isn't it tragic that we came to engineer entire communities around the assumption that every passer-by had a statistically significant probability of being a criminal? Seems a pretty hefty assumption to make. Combining the breadth of such an assumption with the historical record circa mid-century (around every corner, there are Beatniks and Commies and Negroes who want to SUBVERT US ALL!!1!), I can't help but wonder how much of this theory was really more of a fear-based marketing ploy by suburban real-estate developers who needed to sell remote land at inflated prices.